1. Field of the Invention
The present invention relates to a supporting structure for a rotor, wherein at least one holding member is provided for rotatably supporting the shaft of the rotor in the axle tube in a minimum deviation, such that the shaft of the rotor rotates stably and without skew since the starting moment.
2. Description of the Related Art
Applicant""s copending U.S. patent application Ser. No. 09/824,725 filed on Apr. 4, 2001 and entitled SUPPORTING STRUCTURE FOR A ROTOR discloses a supporting structure comprising a metal axle tube, a holding member securely mounted in the axle tube, a supporting member securely mounted in the axle tube and having a supporting portion, and a fixing member securely mounted in the axle tube and having an opening. The holding member includes a hole and an inner flange is formed on an inner periphery defining the hole. A shaft is provided to a center of the rotor and includes an engaging groove. The shaft is extended through the hole of the holding member and the opening of the fixing member with an end face of a distal end of the shaft rotatably resting on the supporting portion of the support member and with the fixing member engaging an engaging groove of the shaft, whereby the shaft and the inner flange of the holding member have a slight contact therebetween.
Applicant""s copending U.S. patent application Ser. No. 09/848,316 filed on May 4, 2001 and entitled SUPPORTING STRUCTURE FOR A ROTOR OF A MOTOR discloses a combination of a rotor and a supporting structure for the rotor. The combination comprises an axle, a fixing member securely mounted in the axle tube, a supporting member securely mounted in a lower end of the axle tube, and a rotor having a shaft base and a shaft extending from the shaft base. The shaft includes an engaging groove. The shaft is extended through the fixing member with an end face of a distal end of the shaft rotatably resting on the supporting member and with the fixing member engaging with the engaging with the engaging groove of the shaft. The shaft further includes an auxiliary supporting section, the auxiliary supporting section and inner periphery of the axle tube having a minimal gap therebetween.
However, when the shaft of the rotor rests in the axle tube, the shaft is merely supported by the flange at one point such that the central axis of the shaft might be deviated from the central axis of the axle tube. As a result, larger wobbling and larger friction occur at the starting moment of the shaft.
The primary object of the present invention is to provide a supporting structure for a rotor, wherein the shaft of the rotor and at least one holding member have a smaller contact area therebetween before rotation, thereby providing a more stable rotation at the starting moment of the shaft.
Another object of the present invention is to provide a supporting structure for a rotor, wherein the rotor rotates stably and thus has a prolonged life while the rotational noise is reduced.
A supporting structure for a rotor in accordance with the present invention comprises two holding members, a supporting member, and a fixing member that is fixed in place. Each holding member comprises a hole and an inner flange formed on an inner periphery defining the hole. The supporting member comprises a supporting portion and the fixing member has a hole. An end of a shaft of a rotor extends through the holes of the fixing members with an end face of the shaft resting on the supporting portion of the supporting member. A retainer is engaged in a retaining groove of the shaft to thereby retain the shaft in place. The shaft and the inner flanges of the holding members have a minimum gap or a slight contact therebetween.
Other objects, specific advantages, and novel features of the invention will become more apparent from the following detailed description and preferable embodiments when taken in conjunction with the accompanying drawings.